NBA season ticket holders have to pay early to get their seats at a “discounted” rate for the next season — usually before the playoffs are over, before free agency has begun.

Or in the case of this year, before they know if there will be games this fall. Hundreds of thousands of people — okay, tens of thousands of people and a lot of corporations — have put their money down already for next season.

If there is a next season.

Legally, the teams have to return the money to ticket holders — with interest — if they hold the money all summer and there are no games this fall.

Knicks fans might be especially interested — season ticket prices in the lower bowl went up 49 percent due to the renovations of Madison Square Garden and because the team is finally worth seeing. The New York Knicks sent out a letter to their season ticket base explaining the situation and what was next, according to the New York Post (via Ball Don’t Lie).

The Post has obtained a letter sent to Knicks season-ticket holders on July 1 which specifies any cancelled games will be refunded with interest on a monthly basis.

According to a person with knowledge of the situation, the lockout interest rate is 1 percent, with calculations beginning Oct. 1. Each letter sent out was personalized.

The letter read, in part, “If any 2011-12 preseason or regular season games are cancelled due to a work stoppage, all Season Subscribers will have the option of receiving a refund with interest on a monthly basis, or have money left on account with interest. More specific details about refunds or credits will be shared at the appropriate time.”

In an ideal world, the Knicks will christen the new Madison Square Garden on Nov. 2 against the Miami Heat. But in reality, November may be more about checks with interest from the team for Knicks season ticket holders.